In general, in a cleaning device used for an image forming apparatus, the major method has been that toner on an image bearing member is removed by continuously bringing a blade made of a material such as urethane rubber into close contact with the image bearing member. In this method, it has been known that foreign matter such as paper powder is caught at the pointed end of a blade whereby the lip of the blade or cleaning failure is caused. As a countermeasure against the problem, there is disclosed in Patent Documents 1 to 3 as shown below a method in which, to remove foreign matter from the pointed end of a blade, an image forming job being run is interrupted to stop the movement of an image bearing member or to rotate it in the reverse direction.
The image forming apparatus described in Japanese Patent Application Publication No. 2002-311771 is provided with a cleaning action of a blade in which a photoreceptor is rotated in the opposite direction to the direction at the time of image formation, and carries out the cleaning action at every prescribed interval of the number of image formation to make it possible to maintain excellent cleaning properties over a long period of time. The prescribed interval is selected based on the number of cartridges used or environmental conditions (temperature or humidity).
The image forming apparatus described in Japanese Patent Application Publication No. 2005-31431 has a cleaning action of a blade in which the apparatus controls a photoreceptor driving motor to stop the photoreceptor, rotate it in the reverse direction and then rotate it in the normal direction during job operations of continuous printing, and returns to the original continuous printing job, and thereby repeats the cleaning action of a blade in a unit of the number of prescribed printing to prevent accumulation of paper powder at an edge of the blade, and to decrease printing failure and improve reliability.
Further, in the image forming apparatus described in Japanese Patent Application Publication No. 2007-328088, a cleaning action of a blade is repeated in which the direction of rotation of the photoreceptor is reversed at every prescribed number of rotations in accordance with the number of rotations of the photoreceptor.
However, it was found that cleaning failure on the intermediate transfer body cannot be sufficiently prevented, in the image forming apparatus comprising an image forming section for forming a toner image on a photoreceptor on which a lubricant is applied, and then transfers the toner onto an intermediate transfer body; a transfer section for transferring the toner image formed on the intermediate transfer body onto a sheet of paper; and an intermediate transfer cleaning section for cleaning the surface of intermediate transfer body by continually bringing a cleaning blade into close contact with the intermediate transfer body, even if the technology described in Patent Documents 1 to 3, that is, the cleaning action of a blade in which, to remove foreign matter such as paper powder from the blade, a printing job is interrupted during an operation of continuous printing job at every prescribed interval to stop rotation of the intermediate transfer body or to rotate it in the reverse direction is carried out.
This problem is one in which, when a continuous printing, in which several-hundreds of sheets are processed, is carried out after intermittent printing was repeated many times, a cleaning failure occurs prior to reaching the above prescribed interval, that is, prior to a cleaning action of the cleaning blade (a return of blade configuration) is carried out.
The object of the present invention is to provide an image forming apparatus capable of preventing cleaning failure which occurs when continuous printing, in which several-hundreds of sheets are processed, is carried out after intermittent printing was repeated many times.